A Peanut Turd can be anything from a rather large chunky piece of shit , wherein you can pick out the exact peanut M&M'S you ate earlier that day , to actually calling someone that's a complete idiot, a Peanut Turd. Hence the phrase "Your not the smartest Peanut in the Turd" !!!!!!

(Guy)Why did you set your mom on fire yesterday ?
( Friend ) :Because man she wouldnt stop coming into my room while I was fondling Rebecca.....
(Guy)Dude you are such an F'ing Peanut Turd !!!!